Hardy bugs thrive in dark, sub−zero Antarctic lake

Washington, Nov 27 (IANS) A community of hardy bugs is thriving in isolated Antarctican water body, in a dark, inhospitable, extremely salty conditions, shows a study.

Lake Vida, the largest of several unique lakes found in the McMurdo Dry Valleys, contains no oxygen, is mostly frozen and possesses the highest nitrous oxide levels of any natural water body on Earth.

A briny liquid six times saltier than sea−water percolates throughout the icy environment that has an average temperature of 13.5 degrees Celsius below zero, the journal Proceedings of the National Academy of Sciences reported.

Previous studies of Lake Vida dating back to 1996 indicate that the brine and its inhabitants have been isolated from outside influences for more than 3,000 years.

"This study provides a window into one of the most unique ecosystems on Earth," reveals Alison Murray, molecular microbial ecologist and polar researcher for the past 17 years at Nevada's Desert Research Institute (DRI), who led the study.

Murray, who has participated in 14 expeditions to the Southern Ocean and Antarctic continent, said: "Our knowledge of geochemical and microbial processes in lightless icy environments, especially at sub−zero temperatures, has been mostly unknown up until now," according to an institute statement.

"This work expands our understanding of the types of life that can survive in these isolated, cryo−ecosystems and how different strategies may be used to exist in such challenging environments," added Murray.

Despite the very cold, dark and isolated nature of the habitat, the report finds that the brine harbours a surprisingly diverse and abundant assemblage of bacteria that survive without a present−day source of energy from the sun.

Murray and her co−authors, including the project's principal investigator Peter Doran of the University of Illinois − Chicago, developed stringent protocols and specialized equipment for their 2005 and 2010 field campaigns to sample the lake brine while avoiding contaminating the pristine ecosystem.